What is the CNC construction set?

I wanted to create a series of desktop (or a little larger) sized CNC machines with interchangeable parts. The idea is to be able to build a series of CNC machines that share many of the same components.

Some of the types of builds I am playing with are:

CNC Plasma Cutter (Shown on the Left)

CNC Heavy Duty Router

CNC 3D Printer

CNC Laser Engraver

CNC Drag Knife

CNC Pen Plotter

CNC Plate Marker

Why not build one machine that does it all?

The machines listed above have very different requirements. For example a heavy duty CNC router makes a poor CNC 3D printer. The 3D printer needs to be very quick and agile. The heavy duty CNC router, needs mass and rigidity to handle the cutting loads. You can build a machine that does both operations, but the performance of at least one or even both will suffer.

Some crossover is possible. For instance a CNC 3D printer can also double as a laser engraver, drag knife, and plate marker.

The CNC Router can also double as a drag knife, plate marker, and pen plotter.

This is the first plasma cutter prototype. It was designed to have a removable top. This allows the plasma cutter to double as a plate marker, drag knife, pen plotter.

I have also successfully added a high end flex shaft tool to double as a light duty router/engraver.

A Little History

A couple years ago, I built a small desktop CNC router that I called Titan. It was designed to hold a full sized router or spindle.

It had a moving table for gantry rigidity with many of the parts cut out of Corian and tempered hardboard.

Eventually, most of these components were replaced with aluminum, as seen in many of my Working With Aluminum series.

Titan, sported a 3HP water colled spindle and served me well for cutting all kinds of parts.

Titan wasn't without issues though. I used unsupported 20 mm shafts as rails. These worked ok but I wanted a desktop that was as rigid as my KRMx02 machines.

I decided to take the machine apart to replace the unsupported rails with supported ones.

The CNC Construction Set was Born

When I started to rebuild the machine, I decided to change things up a little. I found that many of the components could be reused. With some design changes, I could build a foundation that would work for several similar sized CNC machine types.

Note that it is my end goal to gather enough information to start a book series, that will allow others to build their own CNC construction set.

As I move forward with my research and design, I will try different things. You are welcome to join me via the write-ups I will be posting here. I will be making mistakes and back tracking as I experiment, for this reason these pages are not meant as step by step directions or the final design for that matter, as those details will eventually be covered in the books.

Feel free to contact me via the Contact Page (below) if you have any questions or comments.

The Materials

For now I will be using 8020 10 series for the construction set. While this may not be the final extrusion that I decide on, I do have a large quantity of it on hand from my older KRMx01 build.

I don't recommend the 10 series for larger CNC machines due to its lack of rigidity, it does work very well for the size of machines I will be building with the CNC constructions set.

I will also be starting with 20mm supported shafts and trucks for my liner rail system, and 5 start ACME lead screws to drive things. Again, these may not be in the final design, but I do have plenty on hand so its work experimenting with.

Adapter Plates

The key to the design of the CNC construction set are the adapter plates.

Here is the current design of the CNC Construction Set Plasma Cutter.

The adapter plates are used for the carriages, motor/bearing mounts, and tool holders. All shown in red.

When designing a new adapter plate, I almost always make one out of 1/2" Corian. It is easier to machine than aluminum, and much cheaper, as I can get it surplus. I can get an 8 foot Corian counter-top for less than $30 from my local Re-Store.

Once I get past the proof of concept and get the kinks worked out, I will replace the part if needed, with Aluminum.